There is a fputs/stdout in core.stdc.stdio.  std.stdio "public imports" that:

"public import core.stdc.stdio;"

Wondering why:

import core.stdc.stdio : fputs;
import core.stdc.stdio : stdout;

void main()
{
   fputs( cast(const char *)"hello world\n",stdout);
}

compiles and runs, but if I change the imports to:

import std.stdio : fputs;
import std.stdio : stdout;

I get this compile error:

fputs_test.d(11): Error: function core.stdc.stdio.fputs (scope const(char*) s, shared(_IO_FILE)* stream) is not callable using argument types (const(char*), File)

On Tuesday, November 07, 2017 04:34:30 Tony via Digitalmars-d-learn wrote:
> There is a fputs/stdout in core.stdc.stdio.  std.stdio "public imports" that:
>
> "public import core.stdc.stdio;"
>
> Wondering why:
>
> import core.stdc.stdio : fputs;
> import core.stdc.stdio : stdout;
>
> void main()
> {
>     fputs( cast(const char *)"hello world\n",stdout);
> }
>
> compiles and runs, but if I change the imports to:
>
> import std.stdio : fputs;
> import std.stdio : stdout;
>
> I get this compile error:
>
> fputs_test.d(11): Error: function core.stdc.stdio.fputs (scope
> const(char*) s, shared(_IO_FILE)* stream) is not callable using
> argument types (const(char*), File)

stdout in core.stdc.stdio and stdout in std.stdio are two different things. In core.stdc.stdio it's a FILE*, and in std.stdio it's std.stdio.File. Basically, core.stdc.stdio gives you the C version, and std.stdio gives you the D version. However, there is no fputs in std.stdio. Rather, std.stdio publicly imports core.stdc.stdio. So, it's the same fputs in core.stdc.stdio, and it expects a FILE*, whereas since you import stdout from std.stdio, you got the File, not the FILE*. So, they're not compatible.

- Jonathan M Davis

On 07/11/2017 4:34 AM, Tony wrote:
> There is a fputs/stdout in core.stdc.stdio.  std.stdio "public imports" that:
> 
> "public import core.stdc.stdio;"
> 
> Wondering why:
> 
> import core.stdc.stdio : fputs;
> import core.stdc.stdio : stdout;
> 
> void main()
> {
>     fputs( cast(const char *)"hello world\n",stdout);
> }
> 
> compiles and runs, but if I change the imports to:
> 
> import std.stdio : fputs;
> import std.stdio : stdout;
> 
> I get this compile error:
> 
> fputs_test.d(11): Error: function core.stdc.stdio.fputs (scope const(char*) s, shared(_IO_FILE)* stream) is not callable using argument types (const(char*), File)

core.stdc.stdio : stdout https://github.com/dlang/druntime/blob/master/src/core/stdc/stdio.d#L710
std.stdio : stdout https://github.com/dlang/phobos/blob/master/std/stdio.d#L4662

Answer: not the same thing.